The present invention relates to a motor-driven compressor.
Conventionally, a motor-driven compressor has been known that includes a housing, into which refrigerant is drawn, a compression portion, which is accommodated in the housing and compresses fluid, an electric motor, which is accommodated in the housing and drives the compression portion, and a drive circuit, which drives the electric motor. For example, refer to Japanese Laid-Open Patent Publication No. 2003-324900. The publication also describes that the drive circuit is attached to the outer surface of the housing and that heat exchange takes place between the fluid and the drive circuit via the housing to cool the drive circuit.
Depending on the ambient temperature about the motor-driven compressor or the drawn-in fluid temperature, which is the temperature of the fluid drawn into the housing, the temperature of the drive circuit may exceed the upper limit of the guaranteed operation range of the drive circuit or may be lowered below the lower limit of the guaranteed operation range. In such cases, the drive circuit may malfunction. On the other hand, the motor-driven compressor is desired to operate continuously as long as possible in some cases.